Microbial Community Structure of Mesophilic and Low-temperature Partial Nitrification-anammox Reactors: Distribution and Functional Roles of the Core Microbiome.

Microbial community structures in mesophilic and low-temperature anammox and partial nitrification-anammox reactors were exami-ned by a 16S rRNA-gene amplicon sequencing ana-lysis. The anammox bacterium, Jettenia sp., was dominant, and nitrifying bacteria, including Nitrosomonas sp. (aerobic ammonia-oxidizing bacterium) and Nitrospira sp., (nitrite-oxidizing bacterium) coexisted in the bioreactors. Core coexisting bacteria, such as Sulfurisoma sp. and Zeimonas sp., showed oxygen-scavenging and NO reduction potentials. Sulfurisoma-related bacteria are distributed across wastewater treatment plants worldwide, particularly in denitrification systems. These results underscore the ecological and functional importance of microbial consortia in enhancing nitrogen removal efficiency.